Indicating electric fuse



y 1934- l. YELEN INDICATING ELECTRIC FUSE Filed June 16, 1935 R O T N EV m [,sidor YbZaz. BY I 11 r ATTORNEY Patented May 8, 1934 PATENT GFFICEUNITED STATES 2 Claims.

This invention relates to fuses for electric circuits and moreparticularly to fuses having indicators by which the condition of thefusible element may be ascertained. Ordinarily such fuses are grouped inclose relation, rendering it difficult to determine which particularfuse has failed to function, making it necessary to experiment, losingvaluable time in deciding which of the fuses is at fault.

It is therefore one of the objects of the invention to provide astructure in which the fusible element controls the position of a tokenindicating its condition, as being operative or inoperative, by visualinspection.

A further feature is in the provision of means by which new fusibleelements may be substituted for such as become defective by reason ofrupture caused by an overload of current, etc. etc.

Another purpose is to produce a fuse constructed of few and simple partsnot readily liable to disorganization in normal use and which isinexpensive to construct and assemble.

These and other analogous aims and objects are accomplished by the noveldesign, construction and combination of parts hereinafter described andillustrated in the accompanying drawing, constituting a materialcomponent of this disclosure, and in which:

Figure 1 is a plan view of an embodiment of the invention showing thesignal set to indicate an operative condition.

Figure 2 is a similar view of the same but showing the device asindicating an inoperative condition.

Figure 3 is a longitudinal sectional view taken on line 3--3 of Figure1.

Figure 4 is a similar sectional view taken on line 44 of Figure 2.

Figure 5 is another like sectional view taken at a right angle on line55 of Figure 3.

Figure 6 is a transverse sectional view taken on line 66 of Figure 3.

The fuse plug seen in Figures 1 to 6 is of the usual conventional typewith respect to appearance, size and proportion and consists of anonconducting body, as porcelain, generally designated by the numeral15, having an expanded top 16, conical inner end 17 and contains achamber 18 enlarged at its upper portion.

A thin metallic cap 20 over the top 16 is provided with an annularflange 21 spun at its lower portion to tightly engage the bevelled edgeof the plug enlargement 16 to be securely held in place.

At the center of the cap is an opening 23, preferably an elongatedrectangle in outline, and

held by the cap is a disc 24 of transparent material, as mica, seated onthe plug body portion 16.

A metallic sleeve 25 provided with spun threads is tight tted to thebody 15, the sleeve having an inreaching flange 26 set against ashoulder on the body above the conical portion 17, this sleeveconstituting one of the terminal contacts of the fuse plug.

A metallic terminal contact tip 27, at the end of the conical element1'7, is provided with prongs 28 extending upwardly through an opening 19in the lower end of the body, these prongs being eventually bentoutwardly to engage a flange surrounding the opening and by which thetip is rigidly secured to the body.

A fuse strip 30 is soldered to the tip and prongs to extend upwardlyinto the chamber 18, the fuse strip being bent substantially at a rightangle and having its opposite end passed out through a recess 31 in thebody to be engaged 5 by solder, as at 32, with the sleeve 25.

The horizontal portion of the fuse strip 30 is formed with weakeningnotches 33 in its side edges and loosely engaged by these notches is theforked portions 34 of a normally upright bar 35, made of insulatingmaterial, as fiber. The slot 36 freely straddles the fuse strip, whilethe ends of the forks 34 rest on the solder by which the strip 30 issecured to the tip.

The upper portion of the bar is bent to present a loop 37 having plateelements 3839, capable of moving freely in the upper part of the chamber18, closely to but clearing the disc 24.

The plates may bear any preferred inscription, as for instance 0. K. andN. G. respectively and are adapted to appear at the opening 23, whichunder operative conditions discloses the plate 38.

A compression spring 40 is seated at one end in the loop 37 to which itis secured and at the other end abuts the wall of the chamber 18,tending to press the bar 35 to one side, and obviously, if the fusestrip becomes ruptured, the inoperative signal N. G. instantly appearsin view.

While a certain preferred embodiment of this device has been shown anddescribed, it will be understood that changes in the form, arrangements,proportions, sizes and details thereof may be made without departingfrom the scope of the invention as defined in the appended claims.

Having thus described the invention, what is claimed as new and desiredto secure by Letters Patent, is:

1. An indicating electric fuse comprising an insulate chambered bodyhaving an annular surrounding terminal contact and a tip contact, anapertured cap fixed on said body, a fuse element bent to present a rightangle connecting said contacts and having a restricted portion, a forkeddielectric bar engaged on said restricted portion, and resting on thebottom of said body said bar having a loop at one end and mounted tomove freely in the chamber of said body, visual signals on the uppermember of said loop to appear through the aperture in said cap, said barWhile held by the fuse element causing the normal signal to appear, anda spring in said body to move said bar into an abnormal position upondisruption of said fuse element.

2. An indicating electric fuse comprising an insulate chambered bodyhaving spaced terminal contacts, an apertured cap fixed on said body, atransparent disc intervening said cap and body, a fuse elementelectrically connected to said contacts and having a pair of opposednotches in its length, an insulate bar straddling said fuse element atits restricted portion and resting on the bottom of the chambered body,a loop formed in the upper end of said bar, the upper surface of saidloop bearing signals showing through the aperture in said cap relativeto the position of said bar, and a spring in the chamber of said body tourge said bar against said fuse element whereby upon breakage of thefuse element the abnormal signal is displayed.

ISIDOR YELEN.

